DESCRIPTION: This is a proposal to extend the analysis of the carotid ultrasound data collected during the Asymptomatic Carotid Artery Progression Study (ACAPS), a double-masked, placebo-controlled randomized clinical trial of 919 high risk men and women, to observe the contour of the intimal medial thickening (IMT) changes that occurred from baseline through three years of follow up, taking advantage of the multiple measurements taken from multiple sites in the original study.